When it comes to benchmarking top-end cards like Radeon HD 7970, 3DMark Vantage depends too much on the performance of the platform at large, which is especially conspicuous with the CrossFireX configuration. Our six-core CPU overclocked to 4,625 MHz and fast system memory can’t help. The CrossFireX config is only 40% ahead of the single card in Performance mode but the gap grows to 78% in Extreme mode.
The more recent version of 3DMark allows the tandem of the fastest single-GPU cards to show their best: the CrossFireX configuration is 81% and 95% ahead of the single card in the two test modes. That’s closer to our expectations.
Unigine Heaven Demo
The two Radeon HD 7970s are even faster than the single card in Unigine Heaven: by 95% and more. Let’s see what we have in real games, though.
S.T.A.L.K.E.R.: Call of Pripyat
Purchasing two Radeon HD 7970s for S.T.A.L.K.E.R.: Call of Pripyat makes sense if you run the game at the highest settings and at a resolution of 2560x1600. You’ll get twice the frame rate of the single card then. The performance boost from CrossFireX is smaller (20-60%) at 1920x1080 or when full-screen antialiasing is turned off.
Left 4 Dead 2
Despite the high average frame rate, the CrossFireX configuration built out of two top-end graphics cards can provide performance benefits in this game, too. It is 26 to 84% faster than the single card. But of course the single Radeon HD 7970 is also more than enough with its 116 fps at 2560x1600 with 8x MSAA.
Metro 2033: The Last Refuge
The game produced the same results irrespective of whether we enabled FSAA or not. Therefore we tested the graphics cards without FSAA.
The CrossFireX configuration built out of two Radeon HD 7970s may come in handy in Metro 2033: The Last Refuge where the average frame rate increases by 71% and more, making the game playable at 2560x1600. We should note that the bottom speed remains the same as with the single card, though. The new card’s driver obviously needs polishing off.